1. Field of the Invention
The present invention relates to a change-over switch which is suitable for use in the case where, for example, a camera integrated type VTR is connected to a television receiver.
2. Description of the Prior Art
As shown in FIG. 1, hitherto, when a camera integrated type VTR 52 is connected to a television receiver 51 having no video input terminal (an input terminal of a base band signal which is not modulated to a high frequency signal (RF signal)), a cable adapter 54 with a switch to change over a reception signal from a television antenna 53 and an RF output signal from the VTR 52 is used.
Namely, as shown in FIGS. 2 and 3, the cable adapter 54 has input terminals 56A and 56B, an output terminal 57, and a switch 58. For example, F-type connectors are used as the input terminals 56A and 56B and output terminal 57. For instance, a slide switch is used as the switch 58. The input terminals 56A and 56B, output terminal 57, and switch 58 are integrally arranged in a housing 60. As shown in FIG. 3, a terminal 58A of the switch 58 arranged in the housing 60 is connected with the input terminal 56A. A terminal 58B of the switch 58 is connected to the input terminal 56B. A terminal 58C of the switch 58 is connected to the output terminal 57. When the switch 58 is switched so that the terminals 58A and 58C are connected, a signal from the input terminal 56A is taken out from the output terminal 57. When the switch 58 is switched so that the terminals 58B and 58C are connected, a signal from the input terminal 56B is taken out from the output terminal 57.
In FIG. 1, a cable 61 which is led out of the television antenna 53 is connected to the input terminal 56A of the cable adapter 54. One end of a cable 63 is connected to an RF output terminal 65 of the VTR 52. The other end of the cable 63 is connected to the input terminal 56B of the cable adapter 54. One end of a cable 67 is connected to an antenna terminal 69 of the television receiver 51. The other end of the cable 67 is connected to the output terminal 57 of the cable adapter 54.
When a television broadcasting program is displayed by the television receiver 51, the switch 58 of the cable adapter 54 is switched so as to connect the terminals 58A and 58C. When a reproduced image from the VTR 52 is displayed by the television receiver 51, the switch 58 of the cable adapter 54 is switched so as to connect the terminals 58B and 58C.
With such a cable adapter 54 having a switch, the reproduced image from the VTR 52 can be easily displayed by the television receiver 51 having no video input terminal. However, when such a cable adapter 54 is used, three cables 61, 63, and 67 are needed to connect the television receiver 51, VTR 52, and television antenna 53. Thus, there is a problem such that the wiring of the three cables 61, 63, and 67 becomes complicated. On the other hand, before the VTR 52 is connected to the television receiver 51 by using the cable adapter 54, the cable 61 from the television antenna 53 is directly connected to the antenna terminal 69 of the television receiver 51. As compared with the length of the cable 61 at this time, the length of the cable 61 when the cable adapter 54 is used becomes longer. Further, in the conventional cable adapter 54, as shown in FIGS. 2 and 3, since the same type of connectors (for instance, plug type connectors in the case of the NTSC system) are used as the input terminals 56A and 56B and output terminal 57, there is a fear such that the cables are erroneously connected. In addition, there is a large influence by the signal interference among the cables.